An apparatus of a known type for wrapping such o a load is exemplified in Salzsauler U.S. Pat. Nos. 4,934,123 and 4,938,008. In such an apparatus, the load is supported in an elevated position, in which each of its upper and lower corners is exposed. A rotary arm, which is supported by fixed structure above the pallet load, is arranged to be rotatably driven about a vertical axis extending through the load. An upright leg depending from the arm sweeps a cylindrical path around the load as the arm rotates. A carriage is arranged to be upwardly and downwardly driven along the upright leg. Mechanisms on the carriage are arranged to dispense a wrapping film as a film sheet, in which the wrapping film remains substantially at full width, as the arm and the carriage are driven in a suitable manner. As the arm and the carriage are driven, the film sheet is wrapped around the load in spiral patterns, which may be upwardly or downwardly directed.
Furthermore, prior attempts have been made to adapt such an apparatus to dispensing a wrapping film selectively as a film rope, in which the wrapping film is bunched into a rope-like configuration, and as a film sheet, in which the wrapping film remains substantially at full width, and to wrapping such a load with the wrapping film as a film rope before wrapping the load with the wrapping film as a film sheet. However, those attempts have not been entirely satisfactory, since there was no suitable means for guiding a film rope across the upper and lower corners of such as load so as to enable the load to be diagonally or sinusoidally wrapped with the film rope.
Load-wrapping apparatus of related interest are disclosed in Lancaster et al. U.S. Pat. No. 4,418,510, Geisinger U.S. Pat. No. 4,432,185, and Geisinger U.S. Pat. No. 4,619,102.
It would be highly desirable to have loadwrapping apparatus capable of wrapping a load diagonally or sinusoidally with a film rope, which would not only tie the load but would also compress the load vertically, as well as horizontally. As compared to a film sheet of a given material, a film rope of the same material tends to be considerably stronger per unit wrapping area.
Thus, there has been a need, to which this invention is addressed, for improvements in an apparatus of the aforenoted type.